The Social Organization of a Mallard Population in Northern Iowa

Publisher Website
Google Scholar
Abstract
Twenty-two hen and 134 drake mallards were marked during a 2 yr study of mallard (Anas platyrhynchos) breeding activity on Ventura Marsh in north-central Iowa [USA]. During April, sex ratios of mallards observed on breeding areas (54% drakes) were lower than those observed in fields or on open water areas (58% drakes). Numbers of mallards observed declined after the initial influx, and remained relatively constant throughout the breeding season. The number of breeding mallards appears to be limited by pursuit flights. Marked drakes (64), observed at least once with a hen spent an average of 17.6 days on the marsh whereas 70 drakes, not seen with hens, averaged 1.3 days on the area. There was a continual turnover of lone drakes on the study area throughout the breeding season. The nests of 22 marked hens were destroyed between day 10 and 17 of incubation. Four of the hens left the study area, 3 remained but did not remate, and 15 remated. Of 11 identified rematings, 8 hens (73%) returned to their original drake and 3 (27%) changed drakes after losing their nest.

This publication has 2 references indexed in Scilit: